K2.1.5 Multi-rotor LCD Flight Control Board With 6050MPU And Atmel 644PA Firmware Version: 1.6:Pre-installed firmware.DualcopterTricopterY6Quadcopter +Quadcopter XHexcopter +Hexcopter XOctocopter +Octocopter XX8 +X8 XH8H6V8V6Aero 1S AileronAero 2S AileronFlying WingSinglecopter 2M 2SSinglecopter 1M 4S Signal from Receiver: 1520us (5 channels)Signal to ESC: 1520us